global width

procedure main(args)
    lines := []
    width := 0
    format := left
    match("left"|"right"|"center", format <- !args)
    every put(lines,prepare(!&input))
    display(lines, proc(format,3))
end

procedure prepare(lines)
    line := []
    lines ? {
        while (not pos(0)) & (field := tab(upto('$')|0)) do {
            put(line, field)
            width <:= *field
            move(1)
            }
        }
    return line
end

procedure display(lines, format)
    width +:= 1
    every line := !lines do {
        every writes(format(!line, width))
        write()
        }
end